Chinook Salmon Reoccupy Klamath River After Historic Dam Removals
The removal of four hydroelectric dams on the Klamath River has led to a swift return of Chinook salmon to their historical spawning grounds. This follows the completion of the largest dam removal project in U.S. history in 2024, which reconnected over 640 kilometers (approximately 400 miles) of previously inaccessible habitat.
In the first two migratory seasons post-removal, an estimated 7,742 Chinook salmon migrated upstream in 2024, accounting for about 18% of the total basin return. By 2025, this number increased to 13,310, representing 19% of the total return. These figures highlight the rapid recolonization of the salmon, which have now occupied roughly 88% of their historical range.
Environmental benefits have also been observed since the dam removals, including the return of natural water temperature fluctuations and a decrease in harmful algal blooms. Additionally, the prevalence of the parasite Ceratonova shasta among juvenile fish has decreased.
Monitoring efforts by tribal, state, and federal partners, including CalTrout and the California Department of Fish and Wildlife, have documented these changes. The collaborative efforts employ advanced tracking technologies to monitor the salmon's progress and habitat usage.